When you shell out for bottled water, which costs up to 1,900 times more than tap water, you have a right to know what exactly is inside that pricey plastic bottle.

Most bottled makers don’t agree. They keep secret some or all the answers to these elementary questions:

* Where does the water come from?

* Is it purified? How?

* Have tests found any contaminants?

Among the ten best-selling brands, nine — Pepsi’s Aquafina, Coca-Cola’s Dasani, Crystal Geyser and six of seven Nestlé brands — don’t answer at least one of those questions.

Only one — Nestlé’s Pure Life Purified Water — discloses its specific geographic water source and treatment method on the label and offers an 800-number, website or mailing address where consumers can request a water quality test report.

The industry’s refusal to tell consumers everything they deserve to know about their bottled water is surprising.

Since July 2009, when Environmental Working Group released its groundbreaking Bottled Water Scorecard, documenting the industry’s failure to disclose contaminants and other crucial facts about their products, bottled water producers have been taking withering fire from consumer and environmental groups.

A new EWG survey of 173 unique bottled water products finds a few improvements – but still too many secrets and too much advertising hype. Overall, 18 percent of bottled waters fail to list the location of their source, and 32 percent disclose nothing about the treatment or purity of the water. Much of the marketing nonsense that drew ridicule last year can still be found on a number of labels.

EWG recommends that you drink filtered tap water. You’ll save money, drink water that’s purer than tap water and help solve the global glut of plastic bottles.

We support stronger federal standards to enforce the consumer’s right to know all about bottled water.

Until the federal Food and Drug Administration cracks down on water bottlers, use EWG’s Bottled Water Scorecard to find brands that disclose the water’s source location, treatment and quality and that use advanced treatment methods to remove a broad range of pollutants.